High genetic diversity at the extreme range edge: nucleotide variation at nuclear loci in Scots pine (Pinus sylvestris L.) in Scotland

Nucleotide polymorphism at 12 nuclear loci was studied in Scots pine populations across an environmental gradient in Scotland, to evaluate the impacts of demographic history and selection on genetic diversity. At eight loci, diversity patterns were compared between Scottish and continental European populations. At these loci, a similar level of diversity (θsil=~0.01) was found in Scottish vs mainland European populations, contrary to expectations for recent colonization, however, less rapid decay of linkage disequilibrium was observed in the former (ρ=0.0086±0.0009, ρ=0.0245±0.0022, respectively). Scottish populations also showed a deficit of rare nucleotide variants (multi-locus Tajima's D=0.316 vs D=−0.379) and differed significantly from mainland populations in allelic frequency and/or haplotype structure at several loci. Within Scotland, western populations showed slightly reduced nucleotide diversity (πtot=0.0068) compared with those from the south and east (0.0079 and 0.0083, respectively) and about three times higher recombination to diversity ratio (ρ/θ=0.71 vs 0.15 and 0.18, respectively). By comparison with results from coalescent simulations, the observed allelic frequency spectrum in the western populations was compatible with a relatively recent bottleneck (0.00175 × 4Ne generations) that reduced the population to about 2% of the present size. However, heterogeneity in the allelic frequency distribution among geographical regions in Scotland suggests that subsequent admixture of populations with different demographic histories may also have played a role

Genetic variation for sensitivity to a thyme monoterpene in associated plant species

Recent studies have shown that plant allelochemicals can have profound effects on the performance of associated species, such that plants with a history of co-existence with “chemical neighbour” plants perform better in their presence compared to naïve plants. This has cast new light on the complexity of plant–plant interactions and plant communities and has led to debates on whether plant communities are more co-evolved than traditionally thought. In order to determine whether plants may indeed evolve in response to other plants’ allelochemicals it is crucial to determine the presence of genetic variation for performance under the influence of specific allelochemicals and show that natural selection indeed operates on this variation. We studied the effect of the monoterpene carvacrol—a dominant compound in the essential oil of Thymus pulegioides—on three associated plant species originating from sites where thyme is either present or absent. We found the presence of genetic variation in both naïve and experienced populations for performance under the influence of the allelochemical but the response varied among naïve and experienced plant. Plants from experienced populations performed better than naïve plants on carvacrol soil and contained significantly more seed families with an adaptive response to carvacrol than naïve populations. This suggests that the presence of T. pulegioides can act as a selective agent on associated species, by favouring genotypes which perform best in the presence of its allelochemicals. The response to the thyme allelochemical varied from negative to neutral to positive among the species. The different responses within a species suggest that plant–plant interactions can evolve; this has implications for community dynamics and stability

Seedling emergence and establishment of Pinus sylvestris in the Mongolian forest-steppe ecotone

Syftet med studien är att undersöka och beskriva pedagogers uppfattningar av hur de skapar delaktighet och inflytande, i en kommuns förskoleverksamhet och organisation.Mina frågeställningar är hur pedagogerna beskriver sina möjligheter och hinder för att få och skapa delaktighet och inflytande, samt vilka inre och yttre faktorer som finns som påverkar möjligheten för delaktighet och inflytande.För att undersöka detta har jag valt en kvalitativ forskningsansats. Jag har genomfört semistrukturerade intervjuer med sju pedagoger. Det empiriska materialet har bearbetats kvalitativt i en empirinära ansats.I resultatet såg jag att ett större fokus på processkvaliteten behöver läggas och medvetenheten behöver ökas, kring den pedagogiska dokumentationens betydelse.Sammanfattningsvis behöver den undersökta kommunens förskolor en gemensam samsyn i hela systemet i ett förståelsebaserat och tolkande perspektiv som gynnar en långsiktig och hållbar utveckling.Participation and influence in the preschool, a study with teachers in one municipality.The purpose of this study is to explore and describe teacher’s perceptions of how they create participation and influence, in a municipality´s preschool and organization.My questions are how teachers describe their opportunities and barriers to get and create participation and influence, and what internal and external factors that affecting the ability of participation and influence.To examine this, I have chosen a qualitative research approach. I have conducted semi structured interviews, with seven teachers. The empirical data have been processed in a qualitative empirical closely approach.In the result, I found that a greater focus on process quality needs to be added and awareness needs to be increased, on the pedagogic documentations significances.In conclusion, needs the municipal preschools, which have been examined, get a common consensus of the entire system in a understanding based and interpretive perspective, that support a long term and sustainable development